Each mob has its base experience "carved" in it, depending on its class and level.
Then you have the level difference modifier applied by those darned devs which only live to make your life miserable.
Then you have the 1% experience bonus on every 100 points applied in this Attribute.
I don't know all the mobs' base experience.
Because they are quite many.
There is a base formula written somewhere, but I honestly cannot find it.
Pro Tip:
1. Go to a dungeon.
2. Be the same level as the mob is. Preferably be the starting level of each Tier.
3. Defeat the mob.
4. Write down the experience (consider the Intelligence bonus, if you have 100+ points in Intelligence).
5. Repeat the procedure for all the mobs from the Tier.
Mob is 2 levels higher than you -> Multiply the received experience by 1,2 and add 1,1 multiplier for further level differences in order to see mob's base experience.
mob is 2 levels lower than you -> Divide the received experience by 1,2 and add 1,1 multiplier for further level differences in order to see mobs' base experience.
Good luck in creating massive Excel Spreadsheets with all the mobs' experience. All Levels.
Give those spreadsheets to Maeof for his (her) lovely Imperial Hero Project.
Expect him (her) to propose you a marriage.